[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Optional elements and restrictions
Hi Marc, The behaviour you describe is correct. As you know, <DESTINATION_SYSTEM_ID/> is equivalent to <DESTINATION_SYSTEM_ID></DESTINATION_SYSTEM_ID> and none of the specified enumerations match "". I personally don't see how an "empty element" can be considered equivalent to an "omitted element", (e.g. consider <br /> in (early) (X)HTML), so changing the data source seems the correct thing. If reality does not allow that, you could add an additional enumeration of the form: <xs:enumeration value=""/> But that would probably require additional application layer processing to fix it up! HTH, Pete. -- ============================================= Pete Cordell for XML to C++ data binding visit http://www.tech-know-ware.com/lmx ============================================= ----- Original Message ----- From: "Lawson, Marc" <mlawson@r...> To: <xml-dev@l...> Sent: Thursday, November 10, 2005 5:47 PM Subject: Optional elements and restrictions Hi, In my schema, I have an "optional" element that looks like this: <xs:element name="DESTINATION_SYSTEM_ID" minOccurs="0"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:enumeration value="TRUST_PROD"/> <xs:enumeration value="TRUST_TEST"/> <xs:enumeration value="PENSION_PROD"/> <xs:enumeration value="PENSION_TEST"/> </xs:restriction> </xs:simpleType> </xs:element> My instance document will fail validation if the element is provided without any data, as in... <DESTINATION_SYSTEM_ID/> However, the instance document will pass validation if the element is omitted altogether. I am hearing that it is best practice to allow both scenarios - the "empty element" and the "omitted element" - in documents that are provided. Do I need to tell the company that is sending the file to omit the element if it doesn't have data, or can I restructure the schema to only validate elements that have data? Any input is appreciated! Marc Lawson
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